Contact-Killing Antibacterial Polystyrene Polymerized Using a Quaternized Cationic Initiator.

Contact-killing antibacterial materials are attracting attention owing to their ability for sustained antibacterial activity. However, contact-killing antibacterial polystyrene (PS) has not been extensively studied because its chemically stable structure impedes chemical modification. In this study, we developed an antibacterial PS sheet with a contact-killing surface using PS synthesized from 2,2'-azobis-[2-(1,3-dimethyl-4,5-dihydro-1H-imidazol-3-ium-2-yl)]propane triflate (ADIP) as a radical initiator with cationic moieties. The PS sheet synthesized with ADIP (ADIP-PS) exhibited antibacterial activity in contrast to PS synthesized with other azo radical initiators. Surface ζ-potential measurements revealed that only ADIP-PS had a cationic surface, which contributed to its contact-killing antibacterial activity. The ADIP-PS sheets also exhibited antibacterial activity after washing. In contrast, PS sheets containing silver, a typical leachable antibacterial agent, lost all antibacterial activity after the same washing treatment. The antibacterial ADIP-PS sheet demonstrated strong broad-spectrum activity against both Gram-positive and Gram-negative bacteria, including drug-resistant bacteria. Cytotoxicity tests using L929 cells showed that the ADIP-PS sheets were noncytotoxic. This contact-killing antibacterial PS synthesized with ADIP thus demonstrated good prospects as an easily producible antimicrobial material.

Thermally Reversible Gel-Sol Transition of Hydrogels via Dissociation and Association of an Artificial Protein Nanocage.

Oligomeric protein nanocages often disassemble into their subunits and reassemble by external stimuli. Thus, using these nanocages as cross-linkers for hydrogel network structures is a promising approach to allow hydrogels to undergo stimuli-responsive gel-sol transitions or self-healing. Here, we report hydrogels that show a reversible gel-sol transition resulting from the heat-induced dissociation and reassociation of protein nanocages. The hydrogel contained the 60-mer artificial protein nanocage, TIP60, as a supramolecular cross-linker for polyethylene glycol network structures. The hydrogel showed a gel-to-sol transition upon heating at a temperature above the melting point of TIP60 and immediately returned to a gel state upon cooling to room temperature. During the heating and cooling treatment of the hydrogel, small-angle X-ray scattering analysis suggested the dissociation and reassociation of TIP60. Furthermore, we demonstrated redox-responsive cargo release from TIP60 in the hydrogel. These results showed the potential of TIP60 as a component of multi-stimuli-responsive hydrogels.

Multifunctionality of Iodinated Halogen-Bonded Polymer: Biodegradability, Radiopacity, Elasticity, Ductility, and Self-Healing Ability.

A polymer with high contents of ester bonds and iodine atoms was synthesized, exhibiting sufficient biodegradability and radioactivity for biomedical applications. The iodine moieties of the synthesized polyester can generate halogen bonding between molecules, which may develop additional functional properties through the bonding. In this study, poly(glycerol adipate) (PGA) was selected and synthesized as a polyester, which was then adequately conjugated with three different types of iodine compounds via the hydroxy groups of PGA. It was found that the iodine compounds could effectively work as donors of halogen bonding. The thermal analysis by differential scanning calorimetry (DSC) revealed that the glass transition temperature increased with the increase in the strength of interactions caused by π-π stacking and halogen bonding, eventually reaching 49.6 °C for PGA with triiodobenzoic groups. An elastomeric PGA with monoiodobenzoic groups was also obtained, exhibiting a high self-healing ability at room temperature because of the reconstruction of halogen bonding. Such multifaceted performance of the synthesized polyester with controllable thermal/mechanical properties was realized by halogen bonding, leading to a promising biomaterial with multifunctionality.

Compensation for Orientation Birefringence of PMMA by Blending Bottlebrush Polymers Composed of Well-Controlled Graft Chains.

The birefringence of optical polymers is a great issue in optical devices, inhibiting major applications of polymers to optical lenses and films. In this study, we have synthesized effective bottlebrush polymers with which we could attain almost zero birefringence when mixed with optical poly(methyl methacrylate) (PMMA). In detail, the PMMA bottlebrush polymers (PMMA-BBP) were synthesized by the ring-opening metathesis polymerization (ROMP) of norbornene-terminated PMMA macromonomers prepared via atom transfer radical polymerization (ATRP). Linear PMMA and PMMA-BBP were mixed to fabricate blend-film samples (PMMA/PMMA-BBP), which were uniaxially drawn to introduce molecular orientations. Linear PMMA possessed a negative value for its orientation birefringence, while the value of PMMA/PMMA-BBP increased as the PMMA-BBP content increased, whose orientation birefringence could reach almost zero when the ratio of the linear PMMA to PMMA-BBP became 73:27, regardless of the magnitude of the strain. The results reveal that the orientation birefringence of PMMA can be effectively controlled and removed by blending the appropriate content of PMMA-BBP.

[Can Echocardiography Adjust Corrected Contrast Injection Condition in Coronary CT Angiography?]

PURPOSE: The purposes were to search which factor of cardiac function in echocardiography correlates with the CT value, to correct contrast injection conditions with cardiac function in addition to suppress error in the contrast effect between patients, and to achieve the target CT value (350 HU) in coronary computed tomography angiography (CCTA). METHODS: In 112 patients (conventional group), the contrast material was administered at a fractional dose (FD) of 21 mgI/kg/s. We measured the aortic CT value in the coronary origin part. In 112 patients (correction group), the contrast material was administered at corrected injection conditions with the most correlated functional factor and CT value. RESULTS: The CT value of the conventional group was an average of 400.8±51.5 HU. The most correlated factor with the CT value was stroke volume [SV (r=-0.555)]. The CT value of the conventional group was an average of 360±46 HU. The case of the aim CT level was improved from 46% to 74%. In the correction group, the average value of FD was 18.5 mgI/kg/s. This enabled the reduction of the contrast material in 95% of patients. CONCLUSION: The best correlation was obtained between the CT value of coronary arteries and SV. The contrast medium injection conditions were corrected for cardiac function in addition to body weight. As a result, we were able to control the CCTA target CT value of 300 to 400 HU at our hospital.

Finite element analysis of blood clots based on the nonlinear visco-hyperelastic model.

Mechanical thrombectomy has become the standard treatment for patients with an acute ischemic stroke. In this approach, to remove blood clots, mechanical force is applied using thrombectomy devices, in which the interaction between the clot and the device could significantly affect the clot retrieval performance. It is expected that the finite element method (FEM) could visualize the mechanical interaction by the visualization of the stress transmission from the device to the clot. This research was aimed at verifying the constitutive theory by implementing FEM based on the visco-hyperelastic theory, using a three-dimensional clot model. We used the visco-hyperelastic FEM to reproduce the mechanical behavior of blood clots, as observed in experiments. This study is focused on the mechanical responses of clots under tensile loading and unloading because in mechanical thrombectomy, elongation is assumed to occur locally on the clots during the retrieval process. Several types of cylindrical clots were created by changing the fibrinogen dose. Tensile testing revealed that the stiffness (E0.45-value) of clots with fibrinogen could be more than three times higher than that of clots without fibrinogen. It was also found that the stiffness was not proportional to the fibrinogen dose. By fitting to the theoretical curve, it was revealed that the Mooney-Rivlin model could reproduce the hyperelastic characteristics of clots well. From the stress-relaxation data, the three-chain Maxwell model could accurately fit the experimental viscoelastic data. FEM, taking the theoretical models into account, was then carried out, and the results matched well with the experimental visco-hyperelastic characteristics of clots under tensile load, reproducing the mechanical hysteresis during unloading, the stress dependence on the strain rate, and the time-dependent stress decrease in the stress-relaxation test.

Mechanical Property of Polypropylene Gels Associated with That of Molten Polypropylenes.

This study aims to understand the fundamental mechanical relationship between polypropylene (PP)-gels and solid PPs without solvent through mechanical and thermal analyses, by which the mechanical similarities between molten PPs and PP gels were found, leading to the reliable estimate of the mechanical properties of semi-crystalline gels. The gelation of syndiotactic and isotactic polypropylenes (sPP and iPP) was found when PPs were dissolved in 1,2,3,4-tetrahydronaphthalene (tetralin). Interestingly, it was found that the storage modulus of sPP-gel became higher than that of iPP-gel at low PP concentration (<~40 wt%). The result was distinctly different from the result of neat solid PPs (without solvent), where the modulus of solid sPP is generally significantly lower than that of solid iPP. Such inversion behavior in the mechanical property of semi-crystalline gels had not been reported and discussed before. By further investigation of the storage moduli of neat sPP and iPP, it was found that the storage modulus of sPP became higher than that of iPP above the melting points of PP, which was similar to the behavior of the storage moduli observed in the diluted PP-gels. Such similarity between PP-gels and PP melts was also observed within iPP samples with different molecular weights.

Fabrication of Gd-DOTA-functionalized carboxylated nanodiamonds for selective MR imaging (MRI) of the lymphatic system.

Magnetic resonance imaging (MRI) contrast agents with the particle diameter of around 3-10 nm hold the potential to be selectively uptaken by lymphatic vessels and be filtered in the kidney for final excretion. However, there are no existing MRI contrast agents based on gadolinium (Gd) complexes within the size of this range, and thus the selective imaging of the lymphatic system has not yet been achieved. In our previous report, we succeeded in fabricating nano-scale MRI contrast agents by complexing ordinary contrast agents (Gd-diethylenetriaminepentaacetic acid (DTPA)) with carboxylated nanodiamond (CND) particles to conquer this problem. However, DTPA has recently been reported to release Gd ions in the course of time, leading to the potential danger of severe side effects in the human body. In this study, we utilized cyclic-chained DOTA as an alternative chelating material for DTPA to fabricate CND-based MRI contrast agents for the selective lymphatic imaging. The newly fabricated contrast agents possessed the diameter ranging from 3 to 10 nm in distilled water and serum, indicating that these particles can be selectively uptaken by lymphatic vessels and effectively filtered in the kidney. Furthermore, the DOTA-applied CND contrast agents exhibited stronger MRI visibility in water and serum compared to DTPA-applied CND contrast agents. These results indicate that DOTA-applied CND contrast agents are promising materials for the selective MR imaging of lymphatic systems.

Thermophysical Property Measurements of Tetrabutylphosphonium Oxalate (TBPOx) Ionic Semiclathrate Hydrate as a Media for the Thermal Energy Storage System.

With increasing global power demand, thermal energy storage technology could play a role ensuring a sustainable energy supply in power generation from renewable energy sources and power demand concentration. Hydrates have high potential as phase change materials (PCMs) for the use as a thermal energy storage medium. To develop thermal energy storage technology using a hydrate-based material, further investigation of thermophysical properties and the selection of a suitable hydrate are required. Tetrabutylphosphonium oxalate (TBPOx) ionic semiclathrate hydrate contains oxalic acid in salt form, as a guest compound, which is classified as carboxylic acid group with low environmental impact. In the present study, the phase equilibrium temperature and the dissociation heat of TBPOx hydrate were measured. The highest equilibrium temperature of the solid hydrate formed was 9.4°C at the mass fraction 0.35 of TBPOx in aqueous solution. The largest dissociation heat was 186.0 ± 0.5 kJ·kg-1 at the mass fraction of 0.35. Comparing with other PCMs with close phase equilibrium temperatures, TBPOx hydrate is superior in safety and sustainability. These results indicate that TBPOx hydrate would be suitable as the thermal storage medium for the general air conditioning systems.

Synthesis of Thermoplastic Poly(2-methoxyethyl acrylate)-Based Polyurethane by RAFT and Condensation Polymerization.

Thermoplastic solid poly(2-methoxyethyl acrylate) (PMEA)-based polyurethane (PU) is synthesized through the reversible addition-fragmentation chain transfer (RAFT) polymerization and the condensation polymerization, using hydroxyl-terminated RAFT reagents and diisocyanate, respectively. Neat PMEA is a promising antithrombogenic liquid used in the medical fields. The thermoplastic property of the solid PMEA-based PU due to hydrogen bonding is confirmed by the dynamic mechanical analysis (DMA) at temperature below 72 °C. The antithrombogenic property of PMEA-based PU is also analyzed by the platelet adhesion test. The number of platelets on PMEA-based PU is 17 cells per unit area, which is smaller than that on the fluorinated diamond-like carbon (F-DLC), a well-known highly antithrombogenic material. It is concluded that a newly synthesized PMEA-based PU exhibits thermoplastic characteristics with excellent antithrombogenicity.

SANS study on the nano-crystalline network structure of elastic physical gels made of syndiotactic polypropylene.

The structure-property relationship of an elastic physical gel, obtained by simply quenching syndiotactic polypropylene (sPP)/decahydronaphthalene solution with liquid nitrogen, was investigated based on small-angle neutron scattering (SANS) analysis. The SANS analysis revealed that sPP nanocrystals with a constant radius of 4-5 nm existed in the sPP gels regardless of the sPP concentration, whereas the correlation length of the nanocrystals drastically decreased from ∼130 to ∼20 nm upon increasing the sPP concentration from 2 to 12 wt%. The volume fraction and the number density of the sPP nanocrystals increased monotonously with the increase in the sPP concentration. The rheological properties and the melting behavior of the quenched sPP gels were highly consistent with the number density of the nanocrystals calculated from the SANS analysis, strongly suggesting that the sPP nanocrystals actually worked as crosslinking points by inducing elasticity in the quenched sPP gels.

Thermo-Responsive Nanocomposite Hydrogels Based on PEG-b-PLGA Diblock Copolymer and Laponite.

Poly(ethylene glycol)-b-poly(d,l-lactide-co-glycolide) (PEG-b-PLGA) diblock copolymers are widely known as polymeric surfactants for biomedical applications, and exhibit high solubility in water compared to PLGA-b-PEG-b-PLGA triblock copolymers known as gelation agents. In order to overcome the difficulties in the preparation of thermo-responsive hydrogels based on PLGA-b-PEG-b-PLGA due to the low solubility in water, the fabrication of thermo-responsive hydrogels based on PEG-b-PLGA with high solubility in water was attempted by adding laponite to the PEG-b-PLGA solution. In detail, PEG-b-PLGA with high solubility in water (i.e., high PEG/PLGA ratio) were synthesized. Then, the nanocomposite solution based on PEG-b-PLGA and laponite (laponite/PEG-b-PLGA nanocomposite) was fabricated by mixing the PEG-b-PLGA solutions and the laponite suspensions. By using the test tube inversion method and dynamic mechanical analysis (DMA), it was found that thermo-responsive hydrogels could be obtained by using PEG-b-PLGA, generally known as polymeric surfactants, and that the gelation temperature was around the physiological temperature and could be regulated by changing the solution composition. Furthermore, from the structural analysis by small angle neutron scattering (SANS), PEG-b-PLGA was confirmed to be on the surface of the laponite platelets, and the thermosensitive PEG-b-PLGA on the laponite surface could trigger the thermo-responsive connection of the preformed laponite network.

Micropatterning of a 2-methacryloyloxyethyl phosphorylcholine polymer surface by hydrogenated amorphous carbon thin films for endothelialization and antithrombogenicity.

The existing first-generation drug-eluting stent (DES) has caused late and very late stent thrombosis related to incomplete stent endothelialization. Hence, biomaterials that possess sufficient anti-thrombogenicity and endothelialization with the controlled drug release system have been highly required. In this work, we have developed a newly designed drug-release platform composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, a non-thrombogenic polymer, and micropatterned hydrogenated amorphous carbon (a-C:H), a cell-compatible thin film. The platelet adhesion and the endothelial cell adhesion behavior on the micropatterned substrates were investigated in vitro. The results indicated that the micropatterned a-C:H/MPC polymer substrates effectively supported the human umbilical vein endothelial cell (HUVEC) proliferation, while suppressing the platelet adhesion. Interestingly, the HUVEC exhibited different shape and behavior by changing the island size of the micropatterned a-C:H. By introducing both a non-thrombogenic polymer and cell-compatible thin films through a simple patterning method, we demonstrated that the platform had the potential to be utilized as a base material for DES with cell controllability. STATEMENT OF SIGNIFICANCE: The current first-generation drug-eluting stents (DES) would cause late and very late stent thrombosis due to the incomplete endothelialization of the metal stent material. In this work, we have developed a new DES platform composed of a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer micropatterned by hydrogenated amorphous carbon (a-C:H). Two types of differently micropatterned a-C:H stent surface were made. Our studies revealed that the micropatterned a-C:H/MPC polymer substrates could effectively enhance the endothelial cell (EC) proliferation, simultaneously suppressing the platelet adhesion, becoming a highly biocompatible material especially for indwelling devices including a drug-release device. The new drug-release platform could be utilized as a base material for cell-controllable coating on DES.

Nanocomposite injectable gels capable of self-replenishing regenerative extracellular microenvironments for in vivo tissue engineering.

Injectable hydrogels are biomaterials that have the potential to provide scaffolds to cells for in situ tissue regeneration with a minimally invasive implantation procedure. The success of in vivo tissue engineering utilizing injectable gels depends on providing cells with appropriate scaffolds that present an instructive extracellular microenvironment, which strongly influences the survival, proliferation, organization, and function of cells encapsulated within gels. One of the most important abilities of injectable gels to achieve this function is to adsorb and retain a wide variety of requisite bioactive molecules including nutrients, extracellular matrices, and growth/differentiation factors within gels. Previously, we developed nanocomposite injectable gels fabricated by simple combination of common biodegradable copolymers, poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA), and synthetic clay nanoparticles (LAPONITE®). We revealed that the nanocomposite injectable gels strongly adsorb ECM molecules including collagen and heparin within gels and retain them due to the ability of LAPONITE® in synchronization with the degradation of PLGA-PEG-PLGA and subsequent release of the degradation products. Human dermal fibroblast cells cultured on the nanocomposite gels showed enough high cell viability and proliferation for at least a week. Moreover, various kinds of human cells encapsulated within the nanocomposite gels exhibited significantly higher survival, proliferation, and three-dimensional organization in comparison with the PLGA-PEG-PLGA gel, LAPONITE® gel, and Matrigel. Furthermore, transplantation of mouse myoblast cells with the nanocomposite gels in model mice of skeletal muscle injury dramatically enhanced tissue regeneration and functional recovery, whereas cell transplantation with the PLGA-PEG-PLGA gel did not. Thus, the nanocomposite injectable gels possess unique abilities to self-replenish the regenerative extracellular microenvironment within the gels in the body, demonstrating the potential utility of the nanocomposite injectable gels for in vivo tissue engineering.

Self-assembly of peptide amphiphiles by vapor pressure osmometry and dissipative particle dynamics.

Peptide amphiphiles are one of the most promising materials in the biomedical field, so much effort has been devoted to characterizing the mechanism of their self-assembly and thermosensitive gelation. In this work, vapor pressure osmometry measurements were carried out to parameterize the thermosensitivity of interactions between peptide amphiphiles in an aqueous solution. The osmometry measurement verified that the peptides became more hydrophobic as temperature increased, which was quantitatively described with the Flory-Huggins χ parameter. Thereafter, a coarse-grained molecular model was used to simulate peptide amphiphiles dissolved in an aqueous solution. The temperature sensitive coarse-grained parameter a HW, which is the repulsive force between the hydrophilic head of the peptide amphiphile and water was estimated from the aforementioned experimentally obtained χ. Furthermore, the effects of concentration and temperature on the self-assembly behavior of peptide amphiphiles were quantitatively studied by dissipative particle dynamics. The simulation results revealed that a HW plays an important role in self-assembly characteristics and in the resulting microstructure of the peptide amphiphiles, which coincides with previous experimental and computational findings. The methodology in quantitatively linking the coarse-grained parameter from experiment and theory provides a sensible foundation for bridging future simulation studies with experimental work on macromolecules.

In vitro basic fibroblast growth factor (bFGF) delivery using an antithrombogenic 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer coated with a micropatterned diamond-like carbon (DLC) film.

In this study, a newly designed drug-release platform composed of an antithrombogenic 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer was introduced, which was impregnated with basic fibroblast growth factor (bFGF) (bFGF/MPC polymer) to enhance the endothelial cell activation. The platform was also coated with an ultrathin micropatterned diamond-like carbon (DLC) film (DLC/bFGF/MPC polymer) to precisely control the drug release rate and the cell compatibility. The resulting DLC/bFGF/MPC polymer could effectively prolong the bFGF release rate by depositing the micropatterned DLC. The number of adherent platelets on the DLC/bFGF/MPC polymer was significantly lower (about 1/14) than that on a currently used stent made of stainless steel (SUS316L), indicating the enhanced antithrombogenicity in the DLC/bFGF/MPC polymer. The proliferation of endothelial cells on the DLC/bFGF/MPC polymer and the DLC/MPC polymer (without bFGF) were also examined. It was found that the optical density of HUVEC on the DLC/bFGF/MPC polymer determined by WST-8 assay was higher by 25%than that on the DLC/MPC polymer (without bFGF) measured after 72 h of incubation. Our results suggest that the released bFGF that contributes to the expression of other growth factors results in the early proliferation of the HUVEC on the DLC/bFGF/MPC polymer. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3384-3391, 2017.

Effects of salt concentrations of the aqueous peptide-amphiphile solutions on the sol-gel transitions, the gelation speed, and the gel characteristics.

Hydrogels made of peptide amphiphiles (PA) have attracted a lot of interest in biomedical fields. Considering the applications of PA hydrogels, the control of the gelation speed and the gel characteristics is essential to predominantly determine the usefulness and practicability of the hydrogels. In this work, the effects of the salt concentrations using sodium dihydrogenorthophosphate (NaH2PO4) on the sol-gel transition behaviors, especially the gelation speed and the gel characteristics of the designed PA (C16-W3K) hydrogels in aqueous solution were discussed. It was found that the original solution state before rheological testing was independent of the salt concentration, which was confirmed by observing the self-assembly structures and the peptide secondary structures of PA through transmission electron microscopy (TEM) and circular dichroism spectroscopy (CD). The PA solutions with different salt concentrations, however, presented a profound difference in the gelation speed and the gel characteristics: the solution exhibited higher gelation speeds and higher mechanical properties at higher salt concentrations. Concurrently, the density, the length of wormlike micelles, and the conformational ratio of ß-sheets to α-helices in the equilibrium PA solutions all increased with the increase in the salt concentrations.

Transcranial extracellular impedance control (tEIC) modulates behavioral performances.

Electric brain stimulations such as transcranial direct current stimulation (tDCS), transcranial random noise stimulation (tRNS), and transcranial alternating current stimulation (tACS) electrophysiologically modulate brain activity and as a result sometimes modulate behavioral performances. These stimulations can be viewed from an engineering standpoint as involving an artificial electric source (DC, noise, or AC) attached to an impedance branch of a distributed parameter circuit. The distributed parameter circuit is an approximation of the brain and includes electric sources (neurons) and impedances (volume conductors). Such a brain model is linear, as is often the case with the electroencephalogram (EEG) forward model. Thus, the above-mentioned current stimulations change the current distribution in the brain depending on the locations of the electric sources in the brain. Now, if the attached artificial electric source were to be replaced with a resistor, or even a negative resistor, the resistor would also change the current distribution in the brain. In light of the superposition theorem, which holds for any linear electric circuit, attaching an electric source is different from attaching a resistor; the resistor affects each active electric source in the brain so as to increase (or decrease in some cases of a negative resistor) the current flowing out from each source. From an electrophysiological standpoint, the attached resistor can only control the extracellular impedance and never causes forced stimulation; we call this technique transcranial extracellular impedance control (tEIC). We conducted a behavioral experiment to evaluate tEIC and found evidence that it had real-time enhancement and depression effects on EEGs and a real-time facilitation effect on reaction times. Thus, tEIC could be another technique to modulate behavioral performance.

A nanocomposite approach to develop biodegradable thermogels exhibiting excellent cell-compatibility for injectable cell delivery.

A new class of injectable nanocomposite thermogels having excellent cell-compatibility were developed through cooperative self-assembly of biodegradable poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) copolymer micelles and clay nanosheets for effective cell delivery. This study will be valuable for the establishment of injectable cell delivery technology.

Micropatterning of silica nanoparticles by electrospray deposition through a stencil mask.

This article describes the local deposition, or micropatterning, of silica nanoparticles (NPs) using an electrospray method with a stencil mask. The proposed technique can be carried out in a single step at room temperature and atmospheric pressure under dry conditions, allowing it to be used with water- or vacuum-sensitive materials, and leading to cost reductions and high throughput. An evaluation of the patterning accuracy using a 20 µm thick mask showed that for patterns with line widths greater than 50 µm, the pattern was reproduced with an accuracy greater than 95%. When silver NPs were preferably deposited on the silica NPs using a modified silver mirror reaction, they were found to exhibit strong surface-enhanced Raman scattering effects. The proposed process is readily applicable to the development of high-performance micro total analysis systems.